Question

considered the following in respect matrix A and B same order

Answer 1

in a matrix AB ≠BA

thus 1) (A+B)(A-B) = A²-AB+BA-B²

SO LHS ≠ RHS
1 IS WRONG

AI = IA

2) (A-I)(A+I)= A²+AI-IA-I²

=A²+AI-AI-I²
=A²-I²

2) IS CORRECT

THUS ANSWER IS OPTION 2)